Sealing device for drink packages

ABSTRACT

The invention relates to a sealing device ( 3, 30 ) for sealing off an opening ( 5 ) of a plastic drink package. Said sealing device ( 3, 30 ) has a flexible collar ( 10 ) that is provided with an inward-facing surface ( 45 ) that is subject to the internal pressure. The collar ( 10 ), in the closed position of the sealing device ( 30 ), is functionally linked with a collar rim ( 11 ) of the opening ( 5 ) to be sealed off and is adapted to exert a pressure (K) thereon that increases in proportion to the internal pressure (P).

[0001] The invention relates to a device for sealing drinks packages, inparticular drinks packages of plastic which are under inner pressure,according to the preamble of the independent patent claim

[0002] From the state of the art there are known closures for drinkspackages which are under an inner pressure, e.g. PET bottles. Theclosures of these packages require very large closure forces so that asufficient sealedness is guaranteed between the sealing surfaces. Thehigh operating forces resulting from this represent a disadvantage.Furthermore the closures have a very low failure tolerance and thusdemand a very high precision on manufacture. The manufacture thusentails very great expense.

[0003] In order to achieve a sufficient pressing force and thus anadequate sealedness even with a high inner pressure, the closures knowntoday comprise a thread Only by way of this is it possible to producethe required closure forces. On opening the closures the thread iscumbersome because it inhibits the escaping gas.

[0004] The most common closures are manufactured of plastic by way ofinjection moulding. Today's closures require them to be manufacturedwith very tight tolerances.

[0005] The object of the invention disclosed here lies in specifying adevice for sealing drinks packages, in particular drinks packages ofplastic which are under an inner pressure, which require no largeclosure forces, but however are leakproof even with large innerpressures in the container. In particular the device for sealing shouldbe suitable for closures with a hinge and/or quality seal.

[0006] The object is achieved by the invention defined in the patentclaims.

[0007] The invention lies in a sealing device for sealing an opening ofa drinks package. The sealing device comprises a sealing means which isdesigned and arranged in a manner such that it produces a sealing forcewhich is proportional to the inner pressure and which acts on a rimregion of the opening to be sealed.

[0008] The sealing device is designed such that the sealing effect islargely independent of a large initial force. One sets the sealingeffect or force by way of the design, dimensioning and arrangement ofthe sealing means and the surface exposed to the inner pressure.

[0009] The sealing means is formed completely or partly flexiblecompared to the surrounding elements in a manner such that it deforms asa result of a pressure difference (inner pressure). The sealing effectis achieved in that the deformation of the sealing means is hindered ina targeted manner so that a sealing force arises on account of thehindrance. Materials which may be processed by injection moulding andwhich have a Shore hardness which preferably lies in the region of 20 to80 are preferred. The flexibility of the sealing means which is requiredfor a smooth functioning is dependent on the geometry and the mechanicalproperties of the adjacent regions. Materials which have mechanicalproperties which are similar to those of silicone made good experience.

[0010] The invention disclosed here is especially suitable forsingle-part or multi-part closures of plastic. The sealing means mayintegrally form a part of the closure, but also be formed as a separatepart. When required, the closures are preferably manufactured by way ofmulti-component injection moulding. Thus for example by way of adifferent material selection it is possible to integrate a device with aflexible sealing means into a closure which in comparison is lessdeformable.

[0011] The invention is described in more detail by way of thesubsequent figures. Shown schematically and greatly simplified are:

[0012]FIG. 1 a first embodiment form of a sealing device;

[0013]FIG. 2 a detailed view of FIG. 1;

[0014]FIG. 3 the device of FIG. 1 in an opened position;

[0015]FIG. 4 a hinge closure in the closure position;

[0016]FIG. 5 the hinge closure according to FIG. 4 in an open position;

[0017]FIG. 6 a closure with a further embodiment form of a sealingdevice;

[0018]FIG. 7 the closure according to FIG. 6 in a frontal view;

[0019]FIG. 8 five embodiment forms of sealing means.

[0020]FIG. 1 very schematically shows a closure 1 with a sealing deviceaccording to the invention which serves to seal an opening 5. Therepresentation shows the closure 1 with a closure body 2 and with asealing means 3 in a sectional representation. The closure 1 here islocated on a neck 4 of a container, whose opening 5 it sealingly closes.The sealing means 3 here consists of a separate element which at leastin regions corresponds with inner surfaces of the closure body 2 and issupported on these.

[0021] The sealing means 3 comprises a collar 10 which in thisrepresentation is in releasable active connection with a rim of a neck(in the following neck rim) 11 of the opening 54 to be closed. Thecollar 10 in comparison to the closure body 2 is formed flexibly in amanner such that with an inner pressure it is increasingly is supportedon the neck rim 11 and sealingly closes this by way of this.

[0022] The collar 10 is designed such that on placing the closure 1 ontothe neck 4 it experiences a certain deformation by the neck rim 11 whichproduces an initial sealing effect.

[0023] The closure body 2 comprises two laterally arranged arms 6 whichopen into a ring 7. The ring 7 surrounds the neck 4 and comprisesprojecting blocking elements 8 which are fastened on the ring 7 and inthe closure position are in engagement with a blocking edge 9 radiallyprojecting on the neck 4. The closure 1 is securely closed by way ofthis. The closure 1 may be released in that the ring 7 is deformed bylateral pressing in a manner such that it becomes oval and releases theblocking elements 8.

[0024] The closure 1 comprises means for centering the closure 1 on theneck 4. These means which here are not shown in more detail may bedesigned as radially inwardly projecting ribs. They serve thepositioning of the collar 10 with respect to the rim 11 of the opening 5in the unloaded condition.

[0025]FIG. 2 shows the detail D of FIG. 1. One may recognise a part ofthe closure body 2 and of the sealing means 3. The collar 10 is inactive connection with the neck rim 11 of the opening 5. The forcesacting on account of an inner pressure are represented schematically byway of arrows. The inner pressure acting on the collar 10 has the effectthat the collar is pressed with a force K against the neck rim 11 in amanner such that the opening 5 is sealingly closed The size of theoccuring sealing force K may be set by the design of the collar 10.

[0026] The sealing effect may be additionally increased in that the neckrim 11 or the collar 10 comprises means which lead to a concentration ofthe forces responsible for the sealing effect. One or more annularlyprojecting elements or edges (not shown in more detail) arranged in thecontact region between the collar 10 and the neck rim 11 are suitable.

[0027]FIG. 3 shows the closure according to FIG. 1 in an openedposition. As may be recognised, the blocking elements 7 are no longer inengagement with the blocking edge 9 so that the closure may be freelywithdrawn.

[0028]FIG. 4 shows simplified a hinge closure 20 of plastic in aperspective sectional representation. The hinge closure 20 which here isshown closed comprises a lower part 21 and an upper part 22 which areconnected to one another via a hinge 23 (film hinge). The closure 20 ispreferably manufactured by injection moulding of plastic.

[0029] The lower part 21 comprises an opening 5 which is sealinglyclosed by a sealing means 3. The sealing means 3 comprises a collar 10which is in active connection with a neck rim 11 of the opening 5. Thesealing means 3 is designed such that it exerts a sealing force onto therim 11 which is proportional to the inner pressure, in a manner suchthat the opening is securely closed. The sealing means 3 is also hereformed as a separate means. Of course it may however also be integratedinto the hinge closure 20 or form part of this.

[0030] The upper part 22 comprises a hammer-like blocking element 25which projects on an edge and which in the closure position is inengagement with a corresponding groove element 26 of the lower part 21and closes the hinge closure. The blocking element 25 and the grooveelement 26 are designed in a manner such that they may be removed fromthe mould in an injection moulding mould without additional means suchas slider, etc. The closure 20 may be opened in that the blockingelement 25 is bent to the front relative to the groove element 26, awayfrom the lower part.

[0031]FIG. 5 shows the closure 20 according to FIG. 4 in an openedposition. One may recognise the film hinge 23 which linkedly connectsthe lower part 21 to the upper part 22. The sealing means 3 may berecognised in the inside of the upper part 22. The sealing means 3 isarranged in a bordering 29 which holds the sealing means and limits itslateral extension. The collar 10 of the sealing means 3 in comparison tothe material of the closure consists of a relatively elastic material ina manner such that the collar 10 may be deformed without a great forceeffort.

[0032] The hammer-like blocking element 25 projects freely upwards fromthe edge of the closure upper part 22. The wall thickness correspondsroughly to that of the upper part 22. The blocking element 25 has awider region 27 and a narrower region 28. The narrower region 28 isarranged between the wider region 27 and the upper part 22. The grooveelement 26 which is located at the front on the lower part 21 isdesigned in a manner such that it may be brought into engagement withthe blocking element 25. The blocking element 25 advantageously engagesinto the groove element 26 from the outside. By way of this for exampleit is possible to provide a guarantee seal by way of attachment of afilm which after closure of the closure 20 is applied around this andwhich must be removed before opening for the first time. At the sametime the film is applied around the closure 20, the blocking element 25and the groove element 26 such that the engagement between the blockingelement 25 and the groove element 26 may no longer be released withoutremoving the film.

[0033] The closure 20 is preferably screwed or knocked onto a containerto be closed.

[0034] In a sectional representation FIG. 6 shows a closure 40 with asealing device 30 according to the invention. The sealing device 30 ispart of a closure cap 31 and corresponds with a neck rim 11 of anopening 5. The collar 10 of the sealing device 30 is here arranged at aninner angle of a with respect to the closure cap 31 or the rim 11. Thecollar 10 consists of a material which is flexible with respect to thesurroundings and which is well deformable. The sealing device with thecollar 10 is part of the closure cap 31 or is manufactured as a separateelement and subsequently applied into the closure cap 31. The angle α isdirected to the demands on the sealing effect to be achieved given aninner pressure, the desired initial sealing force and themanufacturability. The inner contour of the collar 10 is preferablyselected such that the collar may be simply removed from the mould onmanufacture by way of injection moulding. According to the field ofapplication one may form the inner surface cylindrically as long as therequired elasticity of the collar 10 is ensured. The outer angle α′ (ofFIG. 8) is selected such that the collar 10 may easily be introducedinto the opening, and on placing onto the neck rim 11 experiences aradial deformation which builds up an annular tension. By way ofexploiting these annular tensions it is possible to produce an initialforce acting sufficiently on the rim even with very elastic material, sothat there results a sufficient initial sealing. By way of theflexibility of the collar 10 inaccuracies are compensated for thesealing. In contrast to the closure known from the state of the art theinvention seals even with large inaccuracies.

[0035] The neck rim 11 is here part of the closure lower part 32, withan inner thread 33. The closure lower part may be screwed onto aconventional PET bottle. Of course the closure lower part 32 may also bedesigned as part of a drinks package. The closure lower part 32comprises two lateral, diametrically opposite closure means which inregions project radially and which in each case have a recess 35widening to the bottom. When the closure cap 31 has been placed on,correspondingly formed upper closure means 36 which are formed on theclosure cap 31 via a web 38 engage into these recesses 35. The upperclosure means 36 at the end of the web 38 comprises a broadening 39which engages into the recess 35 with a positive fit. The closure means34, 36 are designed such they may be manufactured in an injectionmoulding tool without a slider. The inner edge of the recesses 35 whichis directed away from the closure cap 31 comprises an undercut. Thebroadening 39 of the upper closure means 36 engages into this undercutand by way of this secures the closure cap 31 from undesired release.

[0036]FIG. 7 shows the closure 40 of FIG. 6 in a front view. Thegeometry of the closure 40 is selected such that on placing the closurecap 31 onto the closure lower part 32 the collar 10 is deformed slightlyinwards in the direction of the arrow by the active connection with theneck rim 11. The elastic material of the collar 10 resists thisdeformation which results in a pressing on the neck rim 11. Thispressing effects an initial sealing effect. Arising inner pressure actson the inner region of the collar 10 by which means the collar attemptsto extend against the direction of the arrow A. This movement isprevented by the neck rim 11 and effects a concentration of the forcesin this region. The collar 10 is designed such that it conducts forcesinto the interaction region between the collar 10 and the neck rim 11 ina targeted manner and thus a sealing force is produced which increasesproportionally with an increasing inner pressure. The collar 10 may beformed such that on reaching a defined maximal pressure with a closurecap 31 is slips off the neck rim 11 in a targeted manner and is turnedup to the outside so that the overcritical inner pressure is reduced. Adangerous jumping-off of the closure is prevented by way of this. Theinitial sealing effect may be influenced by measures which influence theposition of the collar 10 with respect to the neck rim 11. Thesemeasures include: varying the thickness of the base of the closure cap31; length of the webs 38; material accumulation in the regions of thelower and upper closure means 35, 36 which correspond with one another.By way of this it is possible to set the initial sealing effect in atargeted manner by way of simple measures. Shrinkage problems occurringon curing the plastics on manufacture may be compensated in a targetedmanner.

[0037] The closure cap 31 comprises gas exit regions 40 which on openingeffect a directed escape of gas.

[0038]FIG. 8 shows five various embodiment forms (a to e) of sealingmeans 30 in a perspective sectional representation. With a first sealingmeans 30 the collar 10 is arranged radially inwards. This first sealingmeans corresponds essentially to the sealing means 3 of the FIGS. 1 to5.

[0039] The second sealing means 30 (b) comprises an obliquely inwardlyrunning collar 10. The collar 10 has a constant wall thickness and issupported by ribs 41 arranged on the outside. This embodiment form issuitable for very large inner pressures. The region on which a neck rimlies is indicated by a dashed line 42.

[0040] The third sealing means 30 (c) corresponds essentially to thesealing means of FIGS. 7 and 8. This third sealing means 30 likewisecomprises an inwardly inclined collar 10. The collar 10 has a wallthickness which reduces towards the edge. The pressure surface 45 of thecollar 10 exposed to the inner pressure is shown hatched.

[0041] The fourth sealing means 30 (d) corresponds essentially to thethird sealing means (c). This fourth sealing means however in thesealing region 42 on which it lies on a neck rim comprises projectingannular means which effect a concentration of sealing forces.

[0042] The fifth sealing means 30 comprises a collar 10 which has aninwardly directed (sharp) bend. The shape of the collar effects anadditional concentration of the sealing forces in the sealing region 42.The shown sealing means a to e are in particularly suitable for hingeclosures.

[0043] Further embodiment forms result to the man skilled in the art bythe combination of the features of the described devices.

1. A sealing device (3, 30) for sealing an opening (5) of a drinkspackage of plastic, characterised by a flexible collar (10) whichcomprises an inwardly directed surface (45) exposed to the innerpressure, said collar (10) in a closure position of the sealing device(30) being in active connection with a neck rim (11) of the opening (5)to be sealed, in a manner such that the collar (10) is pressed onto theneck rim (11), wherein the pressing force (K) increases proportionallyto the inner pressure (P).
 2. A sealing device (3, 30) according toclaim 1, characterised in that the collar (10) is directed radiallyinwards.
 3. A sealing device (3, 30) according to claim 1, characterisedin that the collar (10) is designed running obliquely inwards at anangle (α).
 4. A sealing device (3, 30) according to one of the precedingpatent claims, characterised in that the collar (10) and/or the neck rim(11) comprises means which effect a concentration of the sealing force.5. A sealing device (3, 30) according to patent claim 4, characterisedin that the means are a circumferential, concentrically arranged bead.6. A sealing device (3, 30) according to one of the preceding claims,characterised in that the collar (10) has a variable wall thickness. 7.A sealing device (3, 30) according to one of the preceding patentclaims, characterised in that the collar (10) comprises a (sharp) bend.8. A sealing device (3, 30) according to one of the preceding patentclaims, characterised in that the collar (10) is supported by ribs (41).9. A sealing device (3, 30) according to one of the preceding patentclaims, characterised in that the collar (10) has a hardness which liesin the region of 20 to 80 Shore A.
 10. A hinge closure (20) with asealing means (3, 30) according to one of the preceding patent claims.